# 请补充你的代码
import math
a = float(input())
b = float(input())
c = float(input())
s = 0.5 * (a + b + c)
area = math.sqrt(s * (s - a) * (s - b) * (s - c))
L = 2 * s
print(f'周长={L:.2f}')
print(f'面积={area:.2f}')